Telephonically-opesated sound recording- and reproducing machine



Se t. 23 1924 1,509,817

' J. W. OWEN ET AL TELEPHONICALLY OPERATED SOUND RECORDING AND REPRODUGING MACHINE Original Filed Aug. 25, 1916 2 Sheets-Sheet 1 I n? g M D HVVEN wares L 1 J MafiWQM/Git,

Sept. 23, .1924. v 1,509,817

I J. W. OWEN ET AL TELEPHONICALLY OPERATED SOUND RECORDING AND IHB RIF-PRODUCING MACH m F 2 a. 45m 6 m 9 a 36/ 6 L- I m s d 9 1 m 2. WI 1 6 m a a? W 10 wm ?4a 2 Q 33 a} a L d a. 4 6 W 3 i 853 v /Emu. James W Omen; A /64272518 Patented Sept. 23, 1924.

UNITED STATES PATENT OFFICE.

JAMES W. OWEN, O33 SEGANE, PENNSLYVANIA, AND ALBERTIS HEWITT, OF CAMDEN,

NEW JERSEY, ASSIGNORS TO VICTOR TALKING MACHINE COMPANY, A CORPORA- TION OF NEW JERSEY.

TELEIHONIGALLY-OPERATED SOUND RECORDING AND REPRODUCING MACHINE.

Application filed August 25, 1916, Serial No. 116,773.

To all 1.0720172 it may concern.

Be it known that we, James V. OWEN, a citizen of the United States, and a resident of Secane, in the county of Delaware, State of Pennsylvania, and Annnn'ris Hnwrrr, a citizen of the United States, and a resident of Camden, in the county of Camden, State of New Jersey, have ointly invented certain new and useful lmpro vements in Telephoni- Cally-Operated Sound Recording and Reproducing llflachines, whereof the following is a specification, reference being had to the accompanying drawings.

Our invention relates to a telephonic or microphone system adapted more especially for use in the combination, with well known types of sound reproducing machines and our invention has for its principal object to convert a portion of the initial sound waves, which we shall hereinafter term primary sound vibrations, created in a reproducing machine, into what we shall hereinafter term secondary and amplified sound vibrations, by means of a telephonic circuit comprising a novel character of microphone diaphragm, the primary sound waves being deflected in whole or in part to actuate such microphone diaphragm. in the circuit, whereby the primary sound vil'nrations will be made more sonorous and may also be subdivided and delivered at various distances from the origi nal source. When used with a sound reproducing or talking machine, the initial sound waves acted on, deflected in whole or in part and converted into secondary sound vibrations are those mechanically produced by the talking machine proper and discharged through its usual tone arm or other sound conduits.

To these ends our invention comprises the couil'iination with any one of several forms of telephonic circuits. and with the tone arm or other sound conduit of a sound reproducing machine, of a novel means for condnctinp; the sound vibrations from the talking machine apparatus to the telephonic circuit, said means including a novel diaphragm of the microphone which, as hereinafter described. operates in a new way and is peculiarly sensitive to the requirements for creating a a. impressing variations in the telmihonic circuit, the combination also including a novel electrical connectin a1:-

Renewed February 8, 1924.

rangenient of the microphone elements and the electric circuit exterior thereto; also means to operatively and more suitably connect the microphone with the tubular sound discharge of the talking machine and the telephonic circuit, and to electrically connect by wires and adj unctive elements the microphone and the sound amplifier of the reproducing apparatus, which latter may, if desired, be duplicated or pluralized and variously located to reproduce accordingly and at different places, the sound vibrations impressed upon the telephonic circuit, in which latter is included, as usual, a source of electrical energy.

Additionally, our invention includes all of the several novel features of construction and arrznigen'ient hereinafter more specifically specified. I

In the accompanying drawings, Fig. 1 is a plan view which sets out all the portions of the apparatus in a partly diagrammatic manner so far as it relates to the telephonic circuit and parts thereof; Fig. 2 shows in elevation a portion of the sound reproducing apparatus modified by the insertion of the chamber therein upon. which is placed the microphone and its electrical wiring. By the insertion of this chamber the tone arm and the amplifier are somewhat separated vertically: Fig. 3 shows diagrammatically the said chamber with the microphones rcmoved; Fig. 4: shows the chamber and connected parts in enlarged form as compared with the preceding figures, the microphones being sectioned and disposed upon the chamber in their relative posit ons; Fig. 5 shows a front elevation of one microphone with parts broken away at several places to show the parts progrering from the front to the rear; and Fig. 6 shows a section on the vertical diameter of the microphone in Fig. 5.

shown in Fig. l the cabinet 1 of a talking machine, which encloses a suitable motor with connected vertical spindle, carries above the upper surface of the cabinet a turntable 2. operatively connected to the spindle 4. The turntable carries the commercial sound record 8 which by the action of the motor transmitted through the spindle 4c rotates below the sound box 5 from which the vibra tions are transmitted to a sound conduit. The sound QOllduit comprises goose-neck ably positionedthe apertured bracket 11 which carries in coinmunication with. its upper recess the horn or amplifier connection 13, whiclron ts part has a removably connected amplifier 1 1 retained in position therein. The removablebracket 11 is re- I tained in position by the set screw 15 which holdsthe clamp 16 in position to retain the ,amp'lifier;connection 13 in a suitable recess interposed between the brackets '10 and 11 is the vertical portion of the sound conduit 17 to which is joined a sound chamber 18, which flares from the rear foiuvardly andt-hus amplifies the sound as received. Eaces19,-2O and 21 properly apertureiil are formed to receive respectively upon each a microphone 22 which may be attached by means of suitable screws 32 inserted in the screw holes disposed about the aperture 23 in each face. Top and bottom faces 6i and 63 respectively, complete the chamber which is entirely enclosed. V

Ext-ending from each microphone are three wires of the usual three wire system of a differential microphonathe same comprising a. positive wire 24, a neutral wire 26, and a negative wire 25. As seen in the wiring diagram in Fig. 1 the positive wires at the microphones connect with the positive wire from the battery 28, through. the switch 27; all the neutral wires at the microphones, connected to the diaphragms 39, join in the neutral wire 26 which is connected to the opposite side (the negative side) of the battery 23 through the several receivers arranged in parallel in said neutral wire circuit; and the negative wires at the microphones join in the negative wire which leads and is connected to the said opposite (negative) side of the battery 28.

The receivers 29 are of any form well. adapted for use in this connection and are united to amplifiers 30 which amplify the sound received from the telephonic circuit. being placed as wished in such numbers and at such stations as shall serve the purpose of filling the space where the apparatus is in use... I

Referring to Fig. 3 it will be noted that the sound chamber 18 is formed so as to embrace about one-half of the cylindrical surface of the vertical sound conduit 17 between the upper and lower faces of the sound chamber. The extent of the sound chamber is thus proportioned so that the reproduced sound in the conduit 17 freely enters the sound chamber 18 upon the three sides 19., 20 and 21 of which are positioned the microphones 22. There is no reason to limit the proportion of the sound chamber so as to accommodate only these microphones but on the contrary a construction is contemplated wherein fewer or more microphones may be used, so long as the requirement is met that there shall be free entrance for the sound fromthe sound conduit 17 into the sound chamber.

Referring to Figures 4, 5 and G, the microphone is seen to consist of, and be attached to the sound chamber by the following described parts. The rear of the inicrophmic 22 consistsof the positive terminal, plate 31, which is apertured to receive the attach- 111 screws which connect the microphone to the sides; of thesound chamber. Surrounding each screwis a. cylindricali'menrber 33 of insulating material. Interposed between the positlvepl ate 31 and the sides of the sound chamber18 are washers 3 1 of felt or likewise suitable material. In setting up the screws 32 the positiveterminal plate thus firmly contacts with and coinpresses the washer 34: between it, and the sound chamber 18 and isiinsulatcd from the walls of the sound chainber 18 by said washer 34. I p

The positive terminal plate 31 is apertured to 'i'eceive the headset the bolts which extend 113611? the positive terminal plate 31 to the front of the microphone where by nuts'36 all ofit'hepa rts are drawn together and held in proper place. Surrounding the. bolts cylinders of insulate-d materialare placed which extend from the positive terminal plate 31 entirely through to the undersideof the nuts 36.

Referring to Fig, 6 it will be noted that the positive terminal plate 31 extends inwardly and has at the center a shoulder thereon forming a cylindrical portion 37 thereon. Near the corner of the shoulder is a series of apertures 38 of small dimension. These apertures are limited in. number and size conjointly so as to modify the harsh vibrations from the sound chamber 18 passing through the terminal plate to the diaphragm 39 the particular constructioiji of which will later be described. The apertures 38 prevent an excessive action uponthe diaphragm 39 of the vibrations emanating: from the sound chamber.

The shoulder 37 has a flange 40 of proper dimensions to receive the screws 41 which fasten in place the cap 42, there being between said cap and said. flange a plate of relatively thin solid carbon 4'? through which the screws tl pass to their co-alctin'g holes in the flange40.

Upon the'front of the positive terminal plate 31 is positioned a thin washer43 of insulating material which on its inner edge contacts physically with the cylinder of insulating material 62 and with the dia-' phgram 39.

On. the outer side of the diaphragm 39 is placed the neutral terminal plate 44 of the form of a washer in physical and electrical contact with the diaphragm, while on the other side of the neutral terminal plate there is located another washer of insulating material 45.

Next to the insulating washer 45 is positioned the negative terminal plate 46 of form and action similar to the positive terminal plate 31, and which has a similar cylindrical portion 55, and flange 56 such as are found on the positive terminal plate 31. A cap 59 corresponding to the cap 42 is fastened to the flange 56 which by the screws 58 holds the carbon late 60 in place for contact with the carbon particles 49 of the microphone all of which is later set out fully. Near the shoulder 55 there is a circular series of holes 57 similar toholes 38 in the positive terminal plate 31. The holes 57 prevent an air pocket and in doing so permit the diaphragm to move without an interfering air pressure on its outer face.

Next to the negative terminal plate 46 and contacting therewith is a thin washer of insulating material 50 and in contact therewith and in front of insulation 50 is a facing member of mica 51 which extends from the outer edge of the microphone to near the cylindrical shoulder 55. The mica facing member 51 is held in position by means of the flanged nuts 36 on bolts 35 which extend to the rear and are fastened to the positive terminal plate 31 at the inner ends. The. nuts 36 are properly positioned to hold all parts in. lace. As the bolts 35 are merely fastening members, they are carefully surrounded by cylinders of insulating material 62.

' is formed the microphone cell compartment through which the diaphragm 39 passes at or about its center. The flanges 40 and 56 retain two asbestos washers 48 and 61 which are arranged on each side of the diaphragm 39 and extend inwardly to the inner extent of the flanges 40 and 56 and fill the space formed by the said flanges and the cylindrical portions 37 and of the positive and negative terminal plates.

The asbestos washers 48 and 61 contact closely with the diaphragm 39 so as to retain. the carbon particles 49 within the compartmonts provided therefor and in close contact with the diaphragm. As shown in the drawings the space provided for the carbon particles is about two-thirds full of carbon. particles.

lVhile in the foregoing the diaphragm 39 has been referred to as positioned in connection with the other parts of the microphone it is proposed at this place to more particu larly describe the special construction of the diaphragm and state its particular adaptability to the device referred to herein.

Many kinds of diaphragms have been employed in microphones of this class, some of which have not fulfilled the requirements of the particular device; hence, disappointing results have frequently attended the use of the ordinary sort of I microphone diatihragms. lVhile it is not known with any certainty why the, novel character of diaphragm herein disclosed has the particular advantages which have been observed to attend its use, it is believed that it may be due to the facts that a diaphragm with a mica base seems to have the necessary delicate responsive action while in vibratory motion which fits itself to the requirements of a sound reproducing machine, and to the further fact that the layer of always bright smooth silver apparently makes a clean con tact with the carbon particles of the microphone when so constructed and employed therewith in a telephonic circuit, and has consequently the right degree of conductivity best suited to the strength of current used; in addition to which the surface of the deposited silver is smoother and more homogeneous than the surface of formerly used diaphragms; and it further appears to be the case that the atmosphere apparently has little efiect upon the smoothness and brightness of the silvered surface, no tarnishing action being observed for a long time; and the results from tests establish that the silvered mica diaphragm responds completely and satisfactorily to the requirements of a microphone diaphragn'i used in the manner set forth, where the action in receiving and transmitting the vibrations from a talking machine appears to be more delicate than in most of the known microphones.

The diaphragm 39 consists of an inner diaphragm of mica 65 which is entirely covered with a coating of silver. The layers of silver on the respective sides of the mica 65 are designated as 66 and 67. Thus there is provided a flexible: diaphragm of the right degree of flexibility, and at the same time one which is electro-conductive so as to make just the right contact with the carbon parti cles of the microphone.

The deposit of silver is made by treating chine mechan cab net through the turi'r-table spindle roa sdl'ution of silver nitrate in water with strong ammonia and then dissolvingthe'yellow deposit with more ammoniatill clear whenthc'sblution is'poured upon and com pletely covers theihica. At the same time a solution of formaldehyde is poured upon and over the mica diaphragm.

Finally, in order to clear the deposlted silver ammonia is poured over the diaphragm and the dia- 'phragm is'then dried.

tates the sound record under the sound box 111' operative contact therewith through "the intervening needle and the sound waves are passed into the tone arm and therethrough into the vertical sound conduit from which they pass to the sound chamber in part. The sound in the"vert1c'al' sound conduit passes upwardly and over into the usual horn amphher of such machines.

The VlblttlOllS'lll the sound chamber pass to the unicrophone diaphragm installedthereabout whereby he audible vibrations are transformed into electrical pulsations by the action of the microphone and its connected circuit. I

The wires from the respective terminals join and form a'single three wire circuit, as shown in Fig. 1 diagrammatically, wherein is placed a battery or other source of electrical energy, as well as a switch for its'well known purpose.

In the arrangement above described it will now be plain that one side (e. the positive pole) of the battery 28 is thus connected to one plate (e. g. to the positive plate 31) of the microphone; that the opposite side (e. the negative pole) of thebattery 28 is connected to theother plate (e. g. the negative plate' lii) oi the microphone; and that the diaphragms 39 and the neutral plate, ring ofconnection 44 of the microphone,are connectedby the'wire 26 through the receivers 29 to said opposite side (e. the negative pole) of the battery.

There are thus two circuits continuously maintained by the battery; the first being from the positive pole of the battery 28, through wire 2 l,to the'plate 31, through the particles oi: carbon a9 to the diaphragm 39, thence to the neutral plate or ring a l to the connections 53'to the wire 26 thence to the receivers 29 and by wire 26 back to the negative side of the-battery '28; and the second being from the positivepoleof thebattery 28, wire 24, to the plateBI and through the carbon 49, tothediaphragm 39 and thence through the carbon particles 49011 the opposite side of the diaphragm to the negative plate 26 of e the microphone and thence through the connection 54- and wire buck to the negative pole of the battery 28.

' Having thus described our invention, whatwe claim and desire toprotect by Lett' er Patent of the United States is:

'l. 111a sound reproducing apparatus, the combination with means for reproducing sound fronra record,means for conducting the reproduced sound, therefrom including a 'tone am,- an amplifier, and a tubular conductor between said tone arm and said amplifier, ofatiaring sound chamber extending laterally from said tubular conductor and adapted to receive sound therefrom, a microphone coinmunicating with" the interior oi? said chamberpan electrical circuit including a "battery'connectedjto said microphone, areceiver in' said circuit adapted to convert electricaliinpulses into'sound vibrations and an 'aniplifier on said'receiver, said microphone being adapted to respond to the sound vibrations in said chamber and to correspondingly vary the curiient in said circuit.

2. In a sound reproducing apparatus, the combination with 'means for reproducing sound froma record, means for conducting thereproduced sound therefrom comprising atone arm, an amplifier, and a tubular con- "ductor betw'een said tone arm and said amplifier; oii a' sound chamber communicating with the interior of said tubular conductor and adapted to receive sound therefrom, a plurality'of microphones in said chamber, and an electrical circuit in which said microphones are connected in parallel, a receiver adaptedto convert the electrical impulses in said circuit into sound and an amplifier on saidreceiver, said microphones being adapted to respond to the sound vibrzu tions in said chamber and to corresponding ly'vary 'thc current in said circuit.

3. In sound reproducing apparatus, the combination with means for reproducing sound from a sound record, means for conducting the reproduced sounds therefrom, and means for amplifying the conducted reproduced sound, of a flared sound chamber connected at its smaller end to said sound conducting means, a microphone communicating with the interior of said chamber, an electrical Icircuit including a battery connccted'to said:microphone. a receiver vtor converting the electr'ral in'uiulses of: said circuitinto sound vibrations, and an amplifier' on said receiver to amplify said sound vibrations. D

t; In sound reproducing apparatus, the combination with means for reproducing sound from a sound record, means for conducting the reproduced sounds therefrom, and means for amplifying the conducted reproduced sound, of a chamber communicating with said sound conducting means, a difterential microphone communicating with the interior of said chamber, a telephonic re ceiver, a battery having one of its terminals connected to one side of said microphone, and the other of its terminals connected to the other side of said microphone, and a circuit from the diaphragm of said microphone through said receiver to said other terminal of said battery.

5. In a sound reproducing apparatus, the combination with means for reproducing sound from a record, an amplifier, and means to conduct the reproduced sound to said amplifier, of a diiferential microphone communicating With said means to conduct said microphone, a connection from the other terminal of said battery to the other side of said microphone, and a connection between the diaphragm of said microphone and said other terminal of said battery through said receiver.

In Witness whereof we have hereunto set our hands this 24th day of August, A. D. 25 

